I was able to add the vista driver packs located here into my WINPE 3.0 build..
1. Download driverpack
2. Mount .wim (for ease of use i create a folder called mount in the same dir as the wim)
@ deployment tools window type the following
imagex /mountrw winpe.wim 1 mount3. use DISM to install the drivers to the mounted image
(for ease i navigate to the folder where my WIM lives) Recurse add all the drivers including subfolders.
Dism /Image:mount /Add-Driver /Driver:DP_LAN_wnt6-x86_1001x86L /Recurse4. Unmount the image and Commit it
imagex /unmount /commit mount